当 App 从后台收到推送通知或在 iOS 中终止时，无法收听来自 NSNotificationCenter 的通知

Question

我正在 iOS 10 中实现推送通知。一切正常。

但是我需要在APP收到推送通知的时候点击API（不仅在Active状态，而且在background/terminated）。

为此，当 App 收到这样的推送通知时，我使用 NSNotificationCenter 来收听通知：

   - (void)userNotificationCenter:(UNUserNotificationCenter *)center
       willPresentNotification:(UNNotification *)notification
         withCompletionHandler:(void (^)(UNNotificationPresentationOptions))completionHandler {
    NSDictionary *userInfo = notification.request.content.userInfo;
    NSLog(@"Message ID: %@", userInfo[@"gcm.message_id"]);

    NSLog(@"%@", userInfo);

    if( [UIApplication sharedApplication].applicationState == UIApplicationStateInactive )
    {
        NSLog( @"INACTIVE" );
        completionHandler( UNNotificationPresentationOptionAlert );
    }
    else if( [UIApplication sharedApplication].applicationState == UIApplicationStateBackground )
    {
        NSLog( @"BACKGROUND" );
        completionHandler( UNNotificationPresentationOptionAlert );
    }
    else
    {
        NSLog( @"FOREGROUND" );
        completionHandler( UNNotificationPresentationOptionAlert );
    }

    [[NSNotificationCenter defaultCenter] postNotificationName:@"reloadTheTable" object:nil];

}

我正在 ViewController.m 中收听此通知，就像这样

    - (void)viewDidLoad {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reloadTable:) name:@"reloadTheTable" object:nil];
}

 - (void)reloadTable:(NSNotification *)notification
{
// Calling API here
}

当应用程序在前台运行时，这工作正常。但不在后台和终止状态。

我有什么错误或我必须实施的其他事情吗？

Answer 1

From iOS 10, we must add UserNotifications framework and delegate

所以首先我们需要在 appDelegate.h

中做以下事情

#import <UserNotifications/UserNotifications.h>  
@interface AppDelegate : UIResponder <UIApplicationDelegate,UNUserNotificationCenterDelegate>

前景状态

- (void)userNotificationCenter:(UNUserNotificationCenter *)center  
willPresentNotification:(UNNotification *)notification  
withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler  
{  
  NSLog( @"Handle push from foreground" );  
  // custom code to handle push while app is in the foreground  
  NSLog(@"%@", notification.request.content.userInfo);
}

这是背景状态。

所以这里需要添加通知

- (void)userNotificationCenter:(UNUserNotificationCenter *)center  
 didReceiveNotificationResponse:(UNNotificationResponse *)response  
 withCompletionHandler:(void (^)())completionHandler 
{  
  NSLog( @"Handle push from background or closed" );  
 // if you set a member variable in didReceiveRemoteNotification, you  will know if this is from closed or background  
  NSLog(@"%@", response.notification.request.content.userInfo);

  //Adding notification here
  [[NSNotificationCenter defaultCenter] postNotificationName:@"reloadTheTable" object:nil];
}

当 App 从后台收到推送通知或在 iOS 中终止时，无法收听来自 NSNotificationCenter 的通知

Unable to listen notification from NSNotificationCenter when App received push notification from background or terminated in iOS

objective-c

push-notification

apple-push-notifications

nsnotificationcenter

ios